This invention relates to rotary vacuum pumps, and in particular, to rotary vacuum pumps having movable vanes mounted in a rotor which is eccentrically mounted in a cylindrical rotor chamber.
Vane pumps of the general type disclosed are commonly used for fluid pumping and pressure generating applications. Vane pumps used to convey liquid media are disclosed, for example, in German Offenlegungsschriften No. 24 05 574 and No. 24 05 575. A vane pump for generating a vacuum for, e.g., a vacuum-operated brake booster in an automobile, is disclosed in commonly-owned U.S. Pat. No. 4,231,727.
In these known vane pumps, the rotor shaft is supported in a single bearing, formed by a special bore in the pump housing. The pump housing is provided with a relatively long axial extension projecting from the chamber bottom, which axial extension has a longitudinal bore. The rotor shaft extends through the extension bore, and the shaft end projecting from the extension carries at its end a pinion gear or a belt pulley.
The present invention is an improvement over these known vane pumps, and has as one of its objects the provision of a vane pump that is comparatively structurally compact in both its axial dimension and in diameter.